MARINE DEPOSITS OF PATAGONIA 199 



third fourth of about 660 square miles of coarse sand of group E, and the southern 

 fourth of about 560 square miles of medium gravel of group F. 



To the north-east of this ground and lying on the continental slope at the junction of 

 the silt and fine sand grounds lies a patch of about 400 square miles of very coarse 

 gravel of group F. 



An extensive ground about 12,000 square miles in area and of coarse texture lies 

 between the Falkland Islands and the coasts of Patagonia and Tierra del Fuego. It runs 

 from the neighbourhood of Cape San Diego in a north-easterly and north-north- 

 easterly direction as far as lat. 50 S. The middle part of it is a comparatively narrow 

 belt, while the northern and southern ends expand to form wider areas. Most of the 

 northern area, of about 2400 square miles, consists of coarse gravel, of group D at the 

 eastern and western extremities and group C in the centre. The northern half of the 

 belt, about 2000 square miles in area, is of medium gravel of group D. The southern half 

 of the belt and most of the southern area, about 4700 square miles, consist of coarse 

 gravel, of group D on the continental shelf, while on the continental slope deposits of 

 group E occur in the northern part and of group F in the southern. An area of about 

 900 square miles of medium gravel of group A occurs at the southern extremity, and a 

 smaller area of about 200 square miles of coarse sand of group D lies at the western 

 border of the belt in lat. 52 S. 



To the west of the northern area of the preceding ground lies another gravel ground, 

 about 2250 square miles in area, between lat. 50 and 51 S and long. 65 and 66° W. 

 It is wedge-shaped, with its point directed westwards, while its base towards the east is 

 deeply indented. The western part, 650 square miles in area, consists of coarse gravel 

 of group D, the eastern part of 1600 square miles of fine gravel, of group D in the south 

 and group C in the north. 



A small ground of medium gravel, about 350 square miles in area, lies about 40 miles 

 east of Point Gallegos: its deposits belong to group D. A ground of about 450 square 

 miles of very coarse gravel of group E lies off the coast between the entrance of the 

 Strait of Magellan and San Sebastian Bay. About 60 miles east of this ground, half-way 

 between it and the extensive gravel grounds west of the Falkland Islands, lies a small 

 patch of about 650 square miles of coarse sand of group C. 



A gravel ground lies off the south coasts of the Falkland Islands and extends down 

 the continental slope at its eastern and western ends. Its area is about 3250 square 

 miles. The western part of the ground, 980 square miles in area, off West Falkland 

 Island consists of medium gravel and extends over the continental slope. The eastern 

 part, about 1850 square miles in area, off the southern end of Falkland Sound and East 

 Falkland Island consists of coarse gravel, but does not extend down the continental 

 slope nor into Falkland Sound where the ground is fine sand of group B. All the portion 

 of this ground on the continental shelf carries deposits of group A, but where it extends 

 over to the continental slope the deposits are of group B. The eastern extremity of the 

 ground extends down the continental slope south of East Falkland Island and consists 

 of fine gravel of group B. 



